Abstract:

Article Preview

Natural bone has excellent mechanical properties such as high fracture toughness and high flexibility. These properties are achieved by specific microstructure of natural bone that is composed of the organic collagen and inorganic apatite. On the basis of these findings, apatite-polymer hybrids are expected as novel bone substitutes having excellent mehcanical performances and high bone-bonding ability, i.e. bioactivity. In this study, we attempted preparation of apatite-polyglutamic
acid hybrids through biomimetic process that mimics the principle of biomineralization. Simple chemical modification of the polyglutamic acid gel with 1 M (= mol/L) calcium chloride solution provided the gel with apatite-forming ability in simulated body fluid (SBF, Kokubo solution). This type of hybrid is also useful for designing bioactive bone substitutes with injectability, since viscosity of the polyglutamic acid gel can be easily controlled according to degree of cross-linking.

Abstract: We immersed micropores-formed glass fiber reinforced polyamide MXD6 (GFR-MXD6) in SBF and precipitated apatite nuclei in the pores of the substrate by raising both the pH and the temperature of SBF and obtained bioactive GFR-MXD6. By immersing in SBF, hydroxyapatite formation was induced by the apatite nuclei in the pores and grew to the surface of the substrate. High adhesive strength between the formed hydroxyapatite and the substrate was obtained by a mechanical interlocking effect.

Abstract: When the pH or the temperature of a simulated body fluid is raised, fine particles of calcium phosphate are precipitated, which are named apatite nuclei (AN). In this study, we aimed to impart bioactivity to polycaprolactone by incorporating AN. AN-PCL composite films having different weight percentages of AN in PCL were fabricated by solution casting technique, using doctor blade method. Results showed that more than 20 wt.% AN-PCL films were fully covered with hydroxyapatite layer in three days soaking period in SBF.